List of world number one snooker players
Periods

No.
Nationality
Player
From
To
1
Wales
Ray Reardon
3 May 1975
20 April 1981
2
Canada
Cliff Thorburn
21 April 1981
16 May 1982
-
Wales
Ray Reardon (2)
17 May 1982
2 May 1983
3
England
Steve Davis
3 May 1983
29 April 1990
4
Scotland
Stephen Hendry
30 April 1990
4 May 1998
5
Scotland
John Higgins
5 May 1998
1 May 2000
6
Wales
Mark Williams
2 May 2000
6 May 2002
7
England
Ronnie O'Sullivan
7 May 2002
5 May 2003
-
Wales
Mark Williams (2)
6 May 2003
3 May 2004
-
England
Ronnie O'Sullivan (2)
4 May 2004
1 May 2006
-
Scotland
Stephen Hendry (2)
2 May 2006
7 May 2007
-
Scotland
John Higgins (2)
8 May 2007
5 May 2008
-
England
Ronnie O'Sullivan (3)
6 May 2008
3 May 2010
-
Scotland
John Higgins (3)
4 May 2010
26 September 2010
8
Australia
Neil Robertson
27 September 2010
12 December 2010
-
Scotland
John Higgins (4)
13 December 2010
2 May 2011
-
Wales
Mark Williams (3)
3 May 2011
11 September 2011
9
England
Mark Selby
12 September 2011
4 November 2012
10
England
Judd Trump
5 November 2012
9 December 2012
-
England
Mark Selby (2)
10 December 2012
17 February 2013
-
England
Judd Trump (2)
18 February 2013
31 March 2013
-
England
Mark Selby (3)
1 April 2013
9 June 2013
-
Australia
Neil Robertson (2)
10 June 2013
5 May 2014
-
England
Mark Selby (4)
6 May 2014
6 July 2014
-
Australia
Neil Robertson (3)
7 July 2014
10 August 2014
-
England
Mark Selby (5)
11 August 2014
7 December 2014
11
China
Ding Junhui
8 December 2014
14 December 2014
-
Australia
Neil Robertson (4)
15 December 2014
24 January 2015
-
China
Ding Junhui (2)
25 January 2015
8 February 2015
-
England
Mark Selby (6)
9 February 2015
24 March 2019
-
England
Ronnie O'Sullivan (4)
25 March 2019
Present

Question: When was Stephen Hendry ranked world number one (and for how many seasons and were they consecutive or not) and did he ever reach number one again?
Answer: Stephen Hendry was ranked world number one for eight consecutive seasons between 1990 and 1998, and regained the top ranking position for the 2006/2007 season.